Development of antimicrobial nanoemulsion edible coating of xanthan gum incorporated with pomelo peel extract for cheese preservation.

The increasing demand for natural food preservation highlights the potential of plant-based edible coatings. This study developed an active nanoemulsion edible coating using xanthan gum (XG) infused with pomelo peel extract (PPE) for paneer preservation. Pomelo peel extracts prepared using methanol, hexane, and dichloromethane showed methanol extract had the highest phenolic (177.06 ± 0.08 mg GAE/g), flavonoid (19.20 ± 0.12 mg RU/g), and antioxidant activity (70.49 ± 0.23 % DPPH inhibition). Antimicrobial activity was confirmed against spoilage organisms, with the highest inhibition zones for Shigella boydii (28.3 ± 1.1 mm), Bacillus cereus (27.6 ± 0.5 mm), and Rhizopus stolonifer (23 ± 2 mm). The nanoemulsion (1.5 % Tween 80, 0.2 % XG, 2 % PPE) was applied to paneer, significantly reducing microbial counts (yeast and mold: 3.31 ± 0.04 log₁₀ CFU/mL; total plate: 3.52 ± 0.01 log₁₀ CFU/mL) over 15 days at 4 °C. It also reduced weight loss (9.62 ± 0.47 %), maintained pH (4.53 ± 0.2), limited lipid hydrolysis (0.81 ± 0.09 %), and preserved acidity (0.99 ± 0.06 %) and sensory quality. This approach supports sustainable food preservation and citrus peel valorisation.